Paleontologists with the Burke Museum of Natural History and Culture and the University of Washington have discovered a Tyrannosaurus rex, including a very complete skull. The find, which paleontologists estimate to be about ...

There has been a long debate about why dinosaurs were so successful. Say dinosaur, and most people think of the great flesh-eaters such as Tyrannosaurus rex, but the most successful dinosaurs were of course the plant-eaters.

Just how bad was T. rex's bite? New research from the University of Bristol has found that the feeding style and dietary preferences of dinosaurs was closely linked to how wide they could open their jaws.

Pete Larson has discovered thousands of fossils around the world, co-authored three books and led the team that unearthed the largest and most complete Tyrannosaurus rex ever found. But there's one black mark on his record: ...

Tyrannosaurus

Tyrannosaurus (pronounced /tɨˌrænɵˈsɔːrəs/ or /taɪˌrænɵˈsɔːrəs/, meaning 'tyrant lizard') was a genus of theropod dinosaur. The species Tyrannosaurus rex ('rex' meaning 'king' in Latin), commonly abbreviated to T. rex, is a fixture in popular culture. It lived throughout what is now western North America, with a much wider range than other tyrannosaurids. Fossils are found in a variety of rock formations dating to the last three million years of the Cretaceous Period, approximately 68 to 65 million years ago. It was among the last non-avian dinosaurs to exist prior to the Cretaceous–Tertiary extinction event.

Like other tyrannosaurids, Tyrannosaurus was a bipedal carnivore with a massive skull balanced by a long, heavy tail. Relative to the large and powerful hindlimbs, Tyrannosaurus forelimbs were small, though unusually powerful for their size, and bore two clawed digits. Although other theropods rivaled or exceeded Tyrannosaurus rex in size, it was the largest known tyrannosaurid and one of the largest known land predators, measuring up to 13 metres (43 ft) in length, up to 4 metres (13 ft) tall at the hips, and up to 6.8 metric tons (7.5 short tons) in weight. By far the largest carnivore in its environment, Tyrannosaurus rex may have been an apex predator, preying upon hadrosaurs and ceratopsians, although some experts have suggested it was primarily a scavenger. The debate over Tyrannosaurus as apex predator or scavenger is among the longest running debates in paleontology.

More than 30 specimens of Tyrannosaurus rex have been identified, some of which are nearly complete skeletons. Soft tissue and proteins have been reported in at least one of these specimens. The abundance of fossil material has allowed significant research into many aspects of its biology, including life history and biomechanics. The feeding habits, physiology and potential speed of Tyrannosaurus rex are a few subjects of debate. Its taxonomy is also controversial, with some scientists considering Tarbosaurus bataar from Asia to represent a second species of Tyrannosaurus and others maintaining Tarbosaurus as a separate genus. Several other genera of North American tyrannosaurids have also been synonymized with Tyrannosaurus.